Apparatus for centrifugal separation



June 15, 1937. A. E. DUERIG 2,083,899

APPARATUS FOR CENTRIFUGAL SEPARATION Filed Nov. so, 1932 5 sheets-sheet -2 INVENTOR /7/ffeo/ 50er/1g ATTORNEYS June 15, 1937. A DUmG 2,083,899

APPARATUS FOR CENTRIFUGAL SEPARATION Filed Nov. 30, 1932 5 Sheets- Sheet 5 ATTORNEYS June 15, 1937. A. E. DUERIG v A APPARATUS FOR CENTRIFUGAL SEPARATION Filed No,v. 30, 1952 5 Sheets-Sheen'l 4 June 15, 1937. A. E. DUERIG 2,083,399

APPARATUS FOR CENTRIFUGAL SEPARATION Filed Nov. 30, 1932 5 Sheets-Sheet 5 INVENTOR /fred E, 70er/:9

ATTORNEYS Patented June 15, 1937 UNITED STATES PATENT OFFICE APPARATUS FOR CENTRIFUGAL SEPARA- TION Application November 30, 1932, Serial No. 644,997

22 Claims.

This invention relates to a continuous centrifugal separator of a character which will simutaneously separate and discharge substances of different densities, where such denser substances are of a solid to semi-liquid nature and to an improved method of separation.

The object of the invention is to utilize the characteristic of a liquid or semi-liquid mixture of substances of different densities, that by centrifuging, such substance or substances of greater densities precipitate to greater radii in the centrifuging chamber, and the characteristic that the coeiicient of friction of the precipitate is different than that of the lighter substances of the mixture, in an apparatus to form the precipitate centrifugally and to remove and discharge the precipitate while the mixture is centrifuging.

A further object of the invention is to utilize the principle of two high speed continuous circular movements of the same direction but of small relative speed, in conjunction with simple intermediate mechanical means to cause one of the circular movements to actuate the centrifuging means and to cause the other circular movement, together with its relation to the i'lrst circular movement, to actuate the discharging means.

Other objects of the invention are that the apparatus be simple in construction, that no mechanical sliding or rolling surfaces operate within the body of the centrifuging substances, and that the parts constituting the apparatus be not subjected to great wear or stress during operation.

Other objects, and objects relating to details oi construction, combination and arrangement of parts and method of operation, will be described in the following description and the novel features thereof set forth in appended claims.

The invention is illustrated and described as an embodiment thereof which is adapted for sewage separation, although it is in no sense limited to this particular use.

Referring to the drawings,

Fig. 1 is a sectional elevation of an apparatus which embodies this invention;

Fig. 2 is an elevation at right angles to that of Fig. 1, showing on a smaller scale the way the apparatus is supported;

Fig. 3 is a plan View of the drum shown in Fig. 1 which forms the centrifuging chamber, together with some of its associated parts;

Fig. 4 is a sectional elevation of the parts shown in Fig. 3;

Fig. 5`is a sectional plan view taken on the line 5-5 of Fig. 1;

Fig. 5A is a diagrammatic plan View of some of the parts illustrating one of the new methods of operation;

Fig. 6 is a sectional elevation taken on the line 6-6 of Fig. 5;

Fig. 7 is a similar View of a part of the apparatus shown in Fig. 5, the ,section being taken on the line 1-1 of the latter gure;

Figs. 8 and 9 are sectional plan views taken on the lines 8-8 and 9-9 respectively of Fig. 1;

Fig. 10 is a sectional elevation similar to Fig. 1 of a modified form of construction;

Fig. l1 is a sectional plan View taken on the line H-ll of Fig. l0;

Fig. l2 is an elevation of a sleeve and some of its associated parts which are used in the apparatus shown in Fig. 10;

Figs. 13, 14, and 16 are fragmentary sectional plan views illustrating the operation of a part of the mechanism shown in Figs. 10, 11 and l2;

Fig. 17 is a sectional elevation of an apparatus of another form which also embodies this invention; and f Fig. 18 is a plan View of the apparatus shown in Fig. 17, the section being ltaken on the irregular line l-l of Fig. 17.

Referring first to Figs. 1 to 9, 2U is a housing which is supported on a structural beam 2l by a plurality of rubber cushioned ball joints 22, as shown in Fig. 2. 23 designates the upper cover of the housing which forms a housing for supporting bearings 224i and MA which Will be more fully described later. 25 is a plaie aiixed to the lo-wer end of the housing and to an annular member 26 througha resilient gasket 2l. 28 is a cylindrical shell to the lower end of which is affixed a anged ring 29.

3K3 is a motor supported on one side of th housing 28. Through a flexible coupling 3l and a Safety coupling 32, the motor drives pinions 33 and 34 on a shaft 35 in gear casing 35 which is a part of housing 20. These pinions drive gears 31 and 38 respectively through idler gears, as shown in Fig. 9. These pinions and gears are of slightly diierent sizes so that the gears are rotated at a slightly different rate.

The gear 3l, by means of a key 40, rotates a vertical stationary sleeve 4 I. This in turn is connected by a key 42 to rotate a sleeve 43 which, as will appear later, has also a reciprocatory movement. Rollers 44 are afxed to the sleeve 43. A key 45 imparts the rotation of sleeve 43 to sleeve 'these pockets.

Amember 65.

46 which also has a reciprocatory movement related to but different from that of sleeve 43. 41 is an arm pivoted at 48 to sleeve 46, on which arm are a plurality of scraper blades 49.

A key 58 imparts the rotation of sleeve 46 to a vertical hollow tube which drives a spider 52 by means of a key 53. The drum 60 is affixed to the spider 52. From the foregoing description it may be seen that gear 31 rotates all of the parts thus described, namely, the sleeves 4|, 43, 46, tube 5|, spider 52 and the drum 60.

The gear 38 is fixed to a sleeve 54 which carries rotatable pins or rollers 55 and 56. The roller 55 engages a groove in a cam collar 51 which is afxed to the sleeve 43, while the roller 56 engages a cam collar 58 which is afixed to the sleeve 46. Because of the different angular movement of the sleeve 54 which carries the pins or rollers 55 and 56 and that of the cam collars 51 and 58, a reciprocatorymovement is imparted to the cam collars and to the sleeves 43, 46 to which they are affixed. The configuration of the cam grooves in the cam collars 51 and .58 are Ysomewhat different in order to impart a desired relative vertical reciprocation to the roller 44 andv pivot 48. During the reciprocation of sleeve 46 the pivot 48 is moved upwardly from the position in which it is shown'in full lines to that in which it is shown in dotted lines at 48A. At the same time, the roller 44 is moved from the position in which it is shown in full lines to its dotted position at 44A. When the pivot 48 has reached its upper position the blades on arm 41 are moved to such a position that the uppermost blade 49.is in the dotted position shown at 49A, the blades being moved outwardly by centrifugal forceclose to the inner surface of the drum. Before and during the downwardrmovement of the pivot 48 the roller 44 moves downwardly from the position 44Ato position 44B to cause it to force the arm 41 inwardly to the dotted position 41A for a purpose which will appear hereinafter. After the arm 41 has reached its lowest position the roller 44 will be moved upwardly to allow arm 41 to swing outwardly under the action of centrifugal force, until the scraper blades 49 are again close to the inner surface of the drum 68. Thereafter the arm 41'will be raised to draw the scraper blades upwardly over the inner surface of the drum.

The drum 60 is constructed with three vertical -pockets 6|, as shown in Fig. 3, having parallel side walls 62 connected by a curved outer wall 63. The wall 63 flares outwardly from the top to the bottom of the drum, as shown in Figs. 1 and 4. The scraper blades 49 conform to the shape of The lower ends of these outer walls of the pockets converge inwardly, as at 64. 65 is a base axed to the bottom of the drum. This has inner surfaces 66 which form continuations of the surface 64 of the drum pockets. 61 is a central opening through the bottom of base Base 65 has a hub 68 which surrounds the hub 59 of spider 52. A plurality of pipes 10, spirally arranged within the base member, communicate with the center of tube 5| which with the hubs 68 and 59 are laterally perforated. Each pipe communicates with a riser 1| which after making a right angle turn terminates in a nozzle 1 2 discharging into one of the drum pockets 6| intermediate the height thereof.

The base 65 is constructed to form a plate 13 'over the spiralY coils and an upstanding rim 14 (Fig. 9). Outside of the coils are tapered pockets ings 16 at their larger ends. 11 designates a wide portion of pockets 15 opposite which is an out-` wardly and downwardly disposed discharge spout 18.

Centrally disposed under the base 65 is a hous-4 ing 88 which is centered by radially disposed pipes 8|, 82, 83 which in turn are positioned in the ring 29. 84 is a casing in which are bearings 85 for the lower end of the spider hub 59. 86 and 81 are annular troughs supported on the pipes 8 82 and 83. 88 is an annular space between the outer trough 86 and the ring 29.

The lower end of tube 5| which passes through the spider hub 59 is rotatively supported by the bearings 85. Its upper end is similarly supported by the bearings 24 which have been pointed out previously. On its upper end is a cap 39 which runs on an oil thrust bearing 24A. The space underthe outer part of cap 39 is arranged to be filled with oil under pressure which tends to balance the weight of tube 5| and its connected parts.

Before specifically describing the structures shown in the other figures of the drawings I wili point out the operation of the apparatus illus trated in Figs. l to 9. Sludge is introduced into the lower end of tube 5| through pipe 8| and housing 89. Thence it passes through pipes and risers 1| to nozzle 12 through which it is discharged into the drum pockets 6| at low velocity o and at an angle substantially tangential to the path of movement of the nozzle. The spiral shape of the pipes causes the direction of flow to be gradually turned toward the direction of rotation and the nozzle is rotated in the same direction as is the drum. By this arrangement, which is shown in Fig. 5A, the material to be separated may be introduced to the drum at low relative velocity.

The natural effect of centrifugal force is to drive the heavier elements of the mixture to the parts of the centrifuge of greatest diameter. The surfaces 64 and 66 are of such an angle that the precipitate will slide to the part of the drum of greatest diameter. The liquid surface at centrifuging speeds is indicated by the dotted line A. Along the circumference described by the lower end of line A, the effluent passes through orifice 61 and is thrown off by centrifugal force into trough 81 from which it is withdrawn through pipe 82 which is stopped at 82A and connected with trough 81 by orifices 82B (see Fig. 8).

Still lighter material such as oils and fats will fall inside of the rim 14 of the base member 65 into the pockets from which they are discharged by centrifugal force through spouts 18 intoI trough 86. From the latter they are withdrawn through pipe 83 which is stopped at 63A and provided with an orifice 83B, as shown in Fig. 8.

By means of the mechanism which has been described, the scraper blades 49 are caused to slide along the surfaces 63 of the drum pockets 6| during their upward movement. At the end of their upward movement they are moved to the center of the machine before the start of their downward stroke. At the end of the downward stroke the roller 44 is raised to permit the arms 41 to swing outwardly from their dotted line position 41A under the action of centrifugal force to bring the scraper blades 49 to their full line position close to the pocket surfaces 63. During their upward strokes they move the precipitate upwardly step by step until it is discharged over the upper edge of drum 69. A canopy 69, affixed to member 26 deects it downwardly and it falls down inside of the shell 28 and through the bottom thereof. The movement of the scraper blades is slow in order to prevent agitation.

It is to be noted that the scraper blades are not forced outwardly by any positive mechanism so that they are free to move inwardly during their up stroke if forced in by any hard particle in the precipitate. It is also kto be noted that the precipitate, after it has been raised beyond the line A, is subjected to dry spinning so that a large part of the moisture is removed from it before it is discharged. Advantage is taken of the higher coefcient of friction of the precipitate which causes it to stay beyond the liquid surface A when it is raised by the scraper blades.

The slow rate of flow through the pipes lll, risers 1| and nozzles 12 is used to prevent breaking down the sludge into small particles in the discharge pipes before it reaches the centrifuging pockets as some of such particles would be carried olf in the eiiiuent.

The operation thus described is a continuous one, which makes it possible for a comparatively small unit to dewater a large amount of sludge.

The apparatus shown in Figs. 10 to 16 diners from that already7 described in that the drum 60A is constructed without pockets and an angular rotary movement is imparted to the scraper blades on their downward stroke relative to the rotation of the drum. The drum 69A is in this case driven from sleeve 4| by arms 4|A.

The mechanisms shown in Fig. 1 are used to impart to the sleeves 43 and 46 the desired reciprocatory movements. In this case, however, an additional mechanism is employed to rotate the sleeves and to impart to them an angular step by step rotation relative to that of tube upon the downward stroke of these sleeves. This comprises a cam sleeve 90 having a flange afxed to a member 9| which rotates with the tube, in which is an inclined keyway 92, and a vertical keyway 93 surrounding sleeve 99 and slidable thereon is a lower collar 94 having a key 95 which slides in the vertical keyway 93, and an upper collar 96 having a key 91 which slides in the inclined keyway 92. The collars 94 and 9B are rotatably supported within a split collar or sleeve 58A aiiixed to the cam collar 59.

It will be seen that the collar 94 rotates with sleeve 99 and collar 59A and that the reciprocation of collar 96 over sleeve 99 causes it to turn relatively to sleeve 99 and collar 59A, in one direction on its up stroke and in the opposite direction during its down stroke. In the collar 94 are tapered pockets 98 and in the collar 9B are similar tapered pockets 99. In these pockets a-re rollers which engage the inner surfaces of collars 94, 96 and the split collar 58A.

On the upward movement of collars 94 and 96 the rollers in the tapered pockets 98 of collar 94 lock collar 94 to sleeve 58A and impart the rotation of sleeve 90 to sleeve 58A, as shown in Fig. 13, and to cam collar 58 and the parts connected therewith. This means that the sleeves 43 and 45 rotate in unison with tube 5| `and drum 69A diuing their upward stroke and that the upward stroke of scraper blades 49 over the inner surface of the drum is vertical. The relative rotation of collar 96 in the opposite direction during this upward stroke has no effect because it releases the engagement of the rollers in its tapered pockets 99, as shown in Fig. 14.

During the downward-stroke, collar 96 rotates in the same direction as sleeve 90, but more rapidly. The rollers in its tapered pockets 99 are then locked to sleeve 58A and cause the latter to advance a step ahead of sleeve 99. This condition is shown in Fig. 15. At this time the movement of sleeve 58A over collar 94 releases the rollers in its tapered pockets 99, as shown in Fig. 16.

Thus, during each of their downward stroke the scraper blades are moved angularly in relation to the drum so that upon successive upward strokes they are moved over different parts of the inner surface of the drum. The other parts of the operation of this Figs. to 16 structure will be understood from the previous description.

In Figs. 17 and 18 the drum 60B is subdivided into a larger number of pockets GlA, in this case eight, with a correspondingly larger number of sets of scraper blades. In this apparatus the material to be separated is introduced through a pipe |99 into the upper end of a vertical tube 5|A. From the lower end of this tube the material riows into a trough |9| from which it is discharged through radially disposed spouts |92 into the drum. The spouts are positioned intermediate the pockets BIA and intermediate the height of the drum.

The base member |95A is constructed to form a pan |93 which catches the eiiiuent from which f it falls through orifices |94 into a trough |95 which is drained by a pipe |96.

Intermediate trough lill and the pan |93 is a conical pan |97 to protect the effluent from solids falling from the lower scraper blade 49 and to prevent undue agitation.

The operation of this apparatus need not be described specically as it will be understood readily from the previous descriptions.

As has been stated, this invention is not limited to the specific use described. Several constructions have been illustrated to show that it is not limited to any specific form of apparatus. The method of introducing matter to a rotating centrifuge and of separation and dry spinning may be performed in many other forms of apparatus. In fact, I intend no limitations other than those imposed by the appended claims.

What I claim is:

l. A centrifugal separator comprising a drum rotatable about a vertical axis, said drum being open at the top, haring downwardly and having its inner surface subdivided into longitudinal pockets parallel to said axis, an arm for each.

pocket having a pivotal support near its upper end rotatable about the axis of the drum, a scraper on each arm arranged to move upwardly over a surface of one of the pockets, means for imparting a vertical reciprocation to said arms,

and means for holding the arms inwardly during the downward movement of the reciprocation.

2. A centrifugal separator comprising a drum rotatable about a vertical axis, said drum being open at the top, flaring downwardly and having :its inner surface subdivided into longitudinal pockets parallel to said axis, an arm for each pocket having a pivotal support near its upper end rotatable about the axis of the drum, a piurality of vertically spaced Scrapers on each arm arranged to move upwardly over a surface of one of the pockets. means for imparting a vertical reciprocation to said arms, and means for holding the arms inwardly during the downward movement of the reciprocation.

3. A centrifugal separator comprising a drum rotatable about a vertical axis, said drum being open at the top and flaring downwardly to form inclined surfaces curved in vertical cross section with the greatest inclination near the lower end of the drum, the inner surface .of the drum being subdivided into longitudinal pockets, an arm for each pocket having a pivotal support near its upper end rotatable about the axis of the drum, a plurality of vertically spaced Scrapers on each arm arranged to move over vasurface of one of the pockets, means for imparting a vertical recprocation to said arms, means for holding the arms inwardly during the downward movement of the reciprocation, and a base member on the lower end of the drum having an opposite inclination to that of the drum.

4. A centrifugal separator comprising a drum rotatable about a vertical axis, said drum being open at the top, flaring downwardly and having its inner surface subdivided into longitudinal pockets, an arm for each pocket h aving a pivotal support near its upper end rotatable about the axis of the drum, a scraper on each arm arranged to move over a surface -of one of the pockets, means for imparting a vertical reciprocation to said arms, means for holding the arms inwardly during the downward movement of the reciprocation, and means for introducing matter toy the drum intermediate its height.

5. A centrifugal separator comprising a drum rotatable about a vertical axis, said drum being open at the top, flaring downwardly and having its inner surface subdivided into longitudinal pockets, an arm for each pocket having a. pivotal support near its upper end rotatable about the axis of the drum, a plurality of vertically spaced Scrapers on each arm arranged to move over a surface of one of the pockets, means for imparting a vertical reciprocation to said arms, means for holding the arms inwardly during the downward movement of the reciprocation, and means for introducing matter to said pockets intermediate the height of the drum.

6. A centrifugal separator comprising a drum rotatable about a vertical axis, said drum being open at the top and flaring downwardly to form inclined surfaces curved in vertical cross section with the greatest inclination near the lower end of the drum, the inner surface of the drum being subdivided into longitudinal pockets, an arm for each pocket having a pivotal support near its up- 4per end rotatable about the axis of the drum,

a plurality of vertically spaced Scrapers on each arm arranged to move over a surface of one of the pockets, means for imparting a vertical reciprocation to said arms, means for holding the arms inwardly during the downward movement of the `reciprocation, a base member on the lower end of the drum having an opposite inclination to that of the drum, and means for introducing matter tangentially to said pockets intermediate the height of the drum.

7. A centrifugal separator comprising a tapered imperforate drum open at the top, means for introducing matter to the drum intermediate its height, an arm pivoted near one of its ends, a scraper on said arm, and means for vertically reciprocating said arm to raise the heavier parts of the matter which `are forced toward the inner surface of the drum gradually to the smaller part of the drum to finally discharge said parts over the open upper end of the drum.

8. A centrifugal separator comprising a hollow vertical shaft, a tapered imperforate drum open at the top supported on and rotatable with said shaft; means rotating with the shaft for introducing matter through said shaft to the drum intermediate its height, an arm pivoted near one of its ends near said shaft, a scraper on said arm, and means for vertically reciprocating said arm to raise the heavier parts of the matter which are forced toward the inner surface of the drum gradually to the smaller part of the drum to nally discharge said parts over the open upper end of the drum.

9. A centrifugal separator comprising an lmperforate drum vopen at the top and flaring downwardly with the greatest inclination of its lnner surface near its lower end, means for lntroducing matter to the drum intermediate its height, an arm pivoted near one end, a scraper cn said arm, and means for moving said arm vertically and transversely to raise the parts of the matter which are forced toward the inner surface of the drum gradually over the portions of said surface of lesser inclination and to finally discharge said parts over the open upper end of the drum.

10. A centrifugal separator comprising a drum open at the top and bottom and flaring downwardly with the greatest inclination of its inner surface near its lower end, a base member on the lower end of the drum having an opposite inclination to that of the drum, means for introducing matter to the drum intermediate its height, an arm pivoted near one end, a scraper on said arm, and means for moving said 4arm vertically and transversely to raise the heavier parts of the matter which are forced toward the inner surface of the drum over the portions of said surface of lesser inclination and to discharge said parts over the open narrower upper end of the drum, and a receptacle for lighter parts of the matter under the wider lower end of the drum.

ll. A centrifugal separator comprising a vertical shaft, a drum supported'on and rotated by said shaft, a pair of sleeves on the shaft and rotatable therewith, means for imparting reciprocatory movements to said sleeves, a plurality of arms pivoted near their upper ends to one of the sleeves, a scraper on each of said arms, and means actuated by the other sleeve to hold said arms inwardly during their downward stroke.

' l2. A centrifugal separator comprising a vertical shaft, a drum supported on and rotated by said shaft, a pair of sleeves on the shaft and rotatable therewith, means for imparting reciprocatory movements to said sleeves, a plurality f' of arms pivoted near their upper ends to one of the sleeves, a scraper on each of said arms, and means actuated by the other sleeve to force said arms inwardly before the start of their downward stroke and to release the arms at the end of said downward stroke.

13. A centrifugal separator comprising a vertical shaft, a drum supported on and rotated with said shaft, a pair of sleeves on said shaft and rotatable therewith, means for imparting reciprocatory movements to said sleeves, an arm pivoted near its upper end to one of the sleeves, a scraper on said arm, means actuated by the other sleeve to hold 'said arm inwardly during its downward stroke, and means for impartingl an angular movement to the sleeves relative to the rotation of the shaft.

14. A centrifugal separator comprising a vertical shaft, a drum supported on and rotated with said shaft, a pair of sleeves on said shaft# and rotatable therewith, means for imparting reciprocatory movements to said sleeves, a plurality of arms pivoted near their upper ends to one of the sleeves, scrapers on said arms, means actuated by the other sleeve to force said arms inwardly before the start of their downward stroke and to release the arms at the end of said downward stroke, and means for imparting an angular movement to the sleeves relative to the rotation of the shaft during one of the reciprocatory movements of the sleeves.

15. A centrifugal separator comprising a hollow vertical shaft, a drum supported on and rotated by said shaft, said drum being open at the top, flaring downwardly and having portions subdividing its inner surface into longitudinal pockets, and a plurality of pipes extending spirally from the lower end of the shaft, extending upwardly through the subdividing portions of the drum and terminating in circumferentially disposed nozzles in the sides of the pockets intermediate the height of the drum.

16. A centrifugal separator comprising a hollow vertical shaft, a drum supported on and rotated by said shaft, said drum being open at the top, flaring downwardly to form inclined surfaces curved in vertical cross section with the greatest inclination near the lower end of the drum and having portions subdividing its inner surface into longitudinal pockets, a plurality of pipes extending spirally from the lower end of the shaft, extending upwardly through the subdividing portions of the drum and terminating in circumferentially disposed nozzles in the sides of the pockets intermediate the height of the drum, an arm for each pocket having a pivotal support near its upper end rotatable about the axis of the drum, a plurality of vertically spaced scrapers on each arm arranged to move over a surface of one of the pockets, means for imparting a vertical reciprocation to said arms, means for holding the arms inwardly during the downward movement of the reciprocation, a base member on the lower end of the drum having an opposite inclination to. that of the drum, and a plurality of receptacles of different diameters under the lower end of the drum.

17. A centrifugal separator comprising a rotatable drum open at one end, flaring outwardly toward the other end and having its inner surface subdivided into longitudinal pockets, an arm for each pocket having a pivotal support near one of its ends rotatable about the axis of the drum, a scraper on each arm arranged to move over a surface of one of the pockets, means for imparting an axial reciprocation to said arms, and means for holding the arms inwardly during their reciprocatory movement in one direction.

18. A centrifugal separator comprising a rotatable drum open at one end, flaring outwardly toward the other end and having its inner surface subdivided into longitudinal pockets, an arm for each pocket having a pivotal support near one of its ends rotatable about the axis of the drum, a scraper on each arm arranged to move over a surface of one of the pockets, means for imparting an axial reciprocation to said arms, means for holding the arms inwardly during their reciprocatory movement in one direction, and means for introducing matter to the drum intermediate its ends.

19. A centrifugal separator comprising a shaft, a drum supported on and rotated by said shaft, a pair of sleeves on the shaft and rotatable therewith, means for imparting reciprocatory movements to said sleeves, an arm pivoted near one of its ends to one of the sleeves, a scraper on said arm, and means actuated by the other sleeve to hold said .arm inwardly during its reciprocatory movement in one direction.

20. A centrifugal separator comprising a shaft, a drum supported on and rotated with said shaft, a pair of sleeves on the shaft and rotatable therewith, means for imparting reciprocatory movements to said sleeves, a plurality of arms pivoted near one of their ends to one of the sleeves, a scraper on each of the arms, means actuated by the other sleeve to hold said arms inwardly during their reciprocatory movement in one direction, and means for imparting an angular movement to the sleeves relative to the rotation of the shaft.

21. A centrifugal separator comprising a drum open at the top and aring downwardly with the inclination of its inner surface changing gradually to form a greater inclination of said surface near its lower end and less inclination of said surface near its upper end, means for introducing matter to the drum, and means for raising the heavier parts of the matter which are forced toward the inner surface of the drum and discharging said parts over the open upper end of the drum.

22. A centrifugal separator comprising a drum open at the top and flaring downwardly with the inclination of its inner surface changing gradually to form a greater inclination of said surface near its lower end and less inclination of said surface near its upper end, means for introducing matter to the drum to submerge the lower part of the drum whereby separation of the parts of said matter is effected in said submerged part of the drum, and means for raising the heavier parts of the matter out of the submerging matter onto and over the upper part of the drum, the lesser inclination of which is such as to prevent downward movement of said heavier parts to permit it to be drained of liquids, said same raising means being arranged to move the drained heavier parts above the open top of the drum to discharge them.

ALFRED E. DUERIG. 

